Question

How is nitroethane prepared from
i) Ethane
ii) ethyl bromide
iii) acetaldoxime

Answer 1

Hint: Knowing the structure of nitroethane and the product that is asked to form, we can determine the process of its formula. The catalysts and the other condition under which the reaction will take place should also be taken into consideration.

Complete step-by-step answer:
At first, we will see the preparation of nitroethane from ethane. Here is the reaction of the process:

$\begin{align}
  & \text{C}{{\text{H}}_{\text{3}}}-\text{C}{{\text{H}}_{\text{2}}}-\text{HO}-\text{N}{{\text{O}}_{\text{3}}}\text{ }\xrightarrow{\text{423K to 698K}}\text{ C}{{\text{H}}_{\text{3}}}-\text{C}{{\text{H}}_{\text{2}}}-\text{N}{{\text{O}}_{\text{2}}}\text{ + }{{\text{H}}_{\text{2}}}\text{O} \\
 & \text{ Nitroethane} \\
\end{align}$
In the above mentioned process, the ethane is heated with concentrated nitric acid. The temperature of the reaction maintained at 423 K to 698K. The completion of the process ultimately results in the formation of nitroethane.
Now we will see the preparation of nitroethane from ethyl bromide. Here is the reaction of the process.
$\begin{align}
  & \text{C}{{\text{H}}_{\text{3}}}-\text{C}{{\text{H}}_{\text{2}}}-\text{Br + NaN}{{\text{O}}_{\text{3}}}\text{ }\xrightarrow{\text{DMSO}}\text{ C}{{\text{H}}_{\text{3}}}-\text{C}{{\text{H}}_{\text{2}}}-\text{N}{{\text{O}}_{\text{2}}}\text{ + NaBr} \\
 & \text{ ethyl bromide Nitroethane} \\
\end{align}$
In the above process ethyl bromide is treated with sodium nitrite, in the presence of a solvent, which is dimethyl sulphoxide. This is also known as DMSO.
At last we will see the formation of nitroethane from acetaloxime. Here is the equation of the process.

$\begin{align}
  & \text{C}{{\text{H}}_{\text{3}}}-\text{CH=N}-\text{OH }+\text{ (O) }\xrightarrow{\text{trifluoroperoxy acetic acid}}\text{ C}{{\text{H}}_{\text{3}}}-\text{CH}=\text{NO}-\text{OH }\Rightarrow \text{ C}{{\text{H}}_{\text{3}}}-\text{C}{{\text{H}}_{\text{2}}}-\text{NO=O} \\
 & \text{ Acetaldoxime Nitroethane} \\
\end{align}$

In the above process, acetaldoxime is oxidised in the presence of trifluoroperoxy acetic acid, nitroethane is obtained.
So in the above reactions we have clearly mentioned the process by which nitroethane can be obtained from the mentioned compounds.

Additional Information:
Like some other nitrated organic compounds, nitroethane is also used as a fuel additive and a precursor to rocket propellants. Nitroethane is a useful solvent for polymers such as polystyrene and is particularly useful for dissolving cyanoacrylate adhesives.

Note: The industrial preparation of nitroethane includes the treating of propane with nitric acid. This reaction is exothermic and it produces industrially significant nitro alkanes, nitromethane and nitroethane.
Nitroethane is a colourless oil liquid which is similar to nitromethane with just a mild fruity odour.